US4995922A - Oxide-dispersion-hardened superalloy based on nickel - Google Patents

Oxide-dispersion-hardened superalloy based on nickel Download PDF

Info

Publication number
US4995922A
US4995922A US07/295,559 US29555989A US4995922A US 4995922 A US4995922 A US 4995922A US 29555989 A US29555989 A US 29555989A US 4995922 A US4995922 A US 4995922A
Authority
US
United States
Prior art keywords
percent
weight
dispersion
oxide
sub
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US07/295,559
Inventor
Peter Jongenburger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB Schweiz Holding AG
Original Assignee
Asea Brown Boveri AG Switzerland
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Asea Brown Boveri AG Switzerland filed Critical Asea Brown Boveri AG Switzerland
Assigned to ASEA BROWN BOVERI LTD. reassignment ASEA BROWN BOVERI LTD. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: JONGENBURGER, PETER
Application granted granted Critical
Publication of US4995922A publication Critical patent/US4995922A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
    • C22C32/001—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides
    • C22C32/0015—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides with only single oxides as main non-metallic constituents
    • C22C32/0026—Matrix based on Ni, Co, Cr or alloys thereof

Definitions

  • Oxide-dispersion-hardened superalloys based on nickel which, owing to their outstanding mechanical properties at high temperatures, are used in the construction of heat engines subjected to high thermal and mechanical loads. Preferred use as bucket materials for gas turbines.
  • the invention relates to the further development of oxide-dispersion-hardened nickel-base superalloys with overall optimal properties, in particular, in relation to behavior during the secondary recrystallization to achieve a coarse-grain structure and to produce monocrystals of large dimensions.
  • oxide-dispersion-hardened superalloy based on nickel which is composed of the following main constituents:
  • high-temperature superalloys have been developed, in particular, for components of heat engines (gas-turbine buckets).
  • These are nickel-base alloys which contain finely divided dispersoides in the form of oxides. In the case of the latter, these are usually Y 2 O 3 particles.
  • the alloys are used in the state of coarse-grain columnar crystals aligned in the longitudinal axis of the component. The coarser the crystals, the better the mechanical high-temperature properties (resistance to a creep and fatigue strength for comparatively low endurance etc.).
  • one object of this invention is to provide novel, oxide-dispersion-hardened superalloys based on nickel which have an extended range of the temperature limits, compared with known alloys, for carrying out the annealing necessary for the production of coarse grain (secondary recrystallization).
  • the object is, in particular, to provide a process for extending the temperature range of the secondary recrystallization which makes it possible to produce even monocrystals of large dimensions (cross section at least 5 cm 2 ) by suitable annealing processes (for example, "zone annealing").
  • This object is achieved by a superalloy based on nickel as mentioned in the introduction which additionally contains boron in a content of 0.026 to 0.3 percent by weight.
  • This object is further achieved by a process as mentioned in the introduction, which comprises doping the oxide-dispersion-hardened nickel-base superalloy with a boron content of more than 0.011 percent by weight.
  • FIG. 1 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 15 percent by weight of chromium,
  • FIG. 2 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 20 percent by weight of chromium,
  • FIG. 3 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 17 percent by weight of chromium,
  • FIG. 4 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy with low chromium content.
  • FIG. 1 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 15 percent by weight of chromium.
  • 1 is the curve for the variation of the recrystallization temperature
  • 2 is the curve for the variation of the solidus temperature.
  • ⁇ T is the maximum temperature range available for the secondary recrystallization. Below curve 1, no recrystallization takes place and an annealing with the object of growing coarse grain or even a monocrystal is pointless. Above curve 2, liquid phases occur and the unity of the crystals is destroyed. The dispersoides agglomerate and become ineffective as a hardening agent. According to curve 2, although the solidus temperature decreases slightly as the boron content increases, the recrystallization temperature according to curve 1 decreases considerably more markedly, as a result of which ⁇ T is extended.
  • FIG. 2 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 20 percent by weight of chromium.
  • 3 is the curve for the recrystallization temperature, which falls off relatively steeply with increasing boron content, while 4 is the curve for the solidus temperature which has a substantially flatter variation.
  • the temperature range ⁇ T is already approx. 150° C.
  • FIG. 3 relates to a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 17 percent by weight of chromium.
  • 5 is the curve for the variation of the recrystallization temperature, while 6 is that for the variation of the solidus temperature.
  • the temperature range ⁇ T is approx. 145° C.
  • FIG. 4 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy with low chromium content. In the present case the latter was approx. 6 percent by weight. 7 is the curve for the variation of the recrystallization temperature, while 8 is the curve for the variation of the solidus temperature. For a boron content of 0.04 percent by weight, the temperature range ⁇ T is approx. 140° C.
  • the boron-free alloy had the following basic composition:
  • a prismatic body made from the above material containing 0.04 percent by weight of boron and having a thickness of 20 mm, a width of 50 mm and a length of 180 mm were subjected to a zone annealing process. It was possible to obtain longitudinally directed columnar crystals with, on average, a width of 25 mm, a thickness of 8 mm and a length of 60 mm.
  • the boron-free alloy had the following basic composition:
  • Test bodies with systematically increasing boron contents were produced, the boron values being varied between 0 and approx. 0.045 percent by weight. Both the recrystallization temperature and the solidus temperature were determined by conventional methods. FIG. 2 shows the results obtained in the process.
  • the workpiece was subjected to a zone annealing process, and a monocrystal was produced.
  • the boron-free alloy had the following basic composition:
  • a cylindrical body with a diameter of 40 mm and a length of 200 mm was machined from the above material containing 0.035 percent by weight of boron and subjected to a zone annealing process.
  • the recrystallized structure was composed of longitudinally directed columnar crystals with, on average, a thickness on all sides of 10 mm and a length of 130 mm.
  • the alloy had the following basic composition:
  • a semi cylindrical body with a diameter of 55 mm and a length of 220 mm was machined from the above material containing 0.045 percent by weight of boron.
  • the workpiece was subjected to a zone annealing process, a monocrystal being produced.
  • composition of the oxide-dispersion-hardened superalloys is as follows:
  • a further class of alloy has the following composition:
  • the alloy mentioned has the following composition:
  • the novel process relates to the extension of the temperature range of the secondary recrystallization of an oxide-dispersion-hardened nickel-base superalloy during coarse-grain annealing of a workpiece and during annealing to produce a monocrystal of large dimensions having a cross section of at least 10 cm 2 , the oxide-dispersion-hardened nickel-base superalloy being doped with a boron content of more than 0.011 percent by weight.
  • the doping is preferably 0.026 to 0.3 percent by weight of boron or 0.026 to 0.1 percent by weight of boron.
  • the advantages of the claimed alloys and of the novel process are in the greater freedom of the annealing process, in particular, of the zone annealing process, produced by extending the temperature range of the secondary recrystallization. This makes possible for the very first time the complete, satisfactory recrystallization to form coarse, longitudinally directed columnar crystals in the case of large workpiece cross sections to be treated. This is even more so for the annealing of a workpiece to produce a monocrystal of large dimensions.
  • the novel process provides the possibility of producing turbine buckets of large cross section composed of a monocrystal, such as are required for modern industrial gas turbines of high power.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
  • Powder Metallurgy (AREA)

Abstract

Oxide-dispersion-hardened superalloy based on nickel, which is composed of the following main constituents:
______________________________________
Cr = 5-13.95 percent by weight or 14.05-22 percent by weight Al = 2.5-7 percent by weight Mo = 0-2 percent by weight W = 0-15 percent by weight Ta = 0-7 percent by weight Hf = 0-1 percent by weight Ti = 0-3 percent by weight Zr = 0.02-0.2 percent by weight Co = 0-10 percent by weight C = 0-0.2 percent by weight Y2 O3 = 1-2 percent by weight Ni = Remainder, ______________________________________
and which additionally contains boron in a content of 0.026 to 0.3 percent by weight.
A process for extending the temperature range of the secondary recrystallization of an oxide-dispersion-hardened nickel-base superalloy of the above composition during coarse-grain annealing and during the production of a monocrystal with a cross section of at least 5 cm2 by doping with a boron content of at least 0.011 percent by weight.

Description

BACKGROUND OF THE INVENTION Field of the Invention
Oxide-dispersion-hardened superalloys based on nickel which, owing to their outstanding mechanical properties at high temperatures, are used in the construction of heat engines subjected to high thermal and mechanical loads. Preferred use as bucket materials for gas turbines.
The invention relates to the further development of oxide-dispersion-hardened nickel-base superalloys with overall optimal properties, in particular, in relation to behavior during the secondary recrystallization to achieve a coarse-grain structure and to produce monocrystals of large dimensions.
In particular, it relates to an oxide-dispersion-hardened superalloy based on nickel which is composed of the following main constituents:
______________________________________                                    
Cr =          5-13.95  percent by weight or                               
              14.05-22 percent by weight                                  
Al =          2.5-7    percent by weight                                  
Mo =          0-2      percent by weight                                  
W =           0-15     percent by weight                                  
Ta =          0-7      percent by weight                                  
Hf =          0-1      percent by weight                                  
Ti =          0-3      percent by weight                                  
Zr =          0.02-0.2 percent by weight                                  
Co =          0-10     percent by weight                                  
C =           0-0.2    percent by weight                                  
Y.sub.2 O.sub.3 =                                                         
              1-2      percent by weight                                  
Ni =          Remainder.                                                  
______________________________________
It further relates to a process for extending the temperature range of the secondary recrystallization of an oxide-dispersion-hardened nickel-base superalloy during coarse-grain annealing of a workpiece and during annealing to produce a monocrystal of large dimensions having a cross section of at least 5 cm2.
Discussion of Background
The following literature is cited in relation to the general prior art:
G. H. Gessinger, Powder Metallurgy of Superalloys, Butterworths, London, 1984
R. F. Singer and E. Arzt, Conf. Proc. "High Temperature Materials for Gas Turbines", Liege, Belgium, October 1986
J. S. Benjamin, Metall. Trans., 1970, 1, 2943-2951.
In the course of past years, a new class of high-temperature superalloys have been developed, in particular, for components of heat engines (gas-turbine buckets). These are nickel-base alloys which contain finely divided dispersoides in the form of oxides. In the case of the latter, these are usually Y2 O3 particles. The alloys are used in the state of coarse-grain columnar crystals aligned in the longitudinal axis of the component. The coarser the crystals, the better the mechanical high-temperature properties (resistance to a creep and fatigue strength for comparatively low endurance etc.). An attempt is made to achieve the desired structural condition by a process of annealing the forged, hot-pressed or usually extruded, fine-grain semi finished product, "zone annealing" playing a dominating role. In the latter, the workpiece is heated zone-by-zone for a short time above the recrystallization temperature, it being necessary to achieve as high a temperature/path gradient as possible during heating up. This applies to the entire cross section of the workpiece. This requirement encounters difficulties in the case of large cross sections owing to the transverse heat flow it necessitates. There is, in fact, only the temperature range between recrystallization temperature and solidus temperature (appearance of the first liquid phase) available as a "window" for carrying out the annealing process. In the conventional, commercially available oxide-dispersion-hardened nickel-base superalloys, this range is comparatively narrow and is inadequate for converting workpieces of large cross section successfully to coarse grain and, in the ideal case, into a monocrystal.
There is therefore an extreme need to improve the recrystallization conditions of oxide-dispersion-hardened superalloys, in particular, for greater freedom in the choice of working parameters for a coarse-grain annealing and for annealing to produce monocrystals of large dimensions.
As the prior art and as an example of a known conventional precipitation-hardenable, oxide-dispersion-strengthened nickel-base superalloy, mention is made of the alloy with the trade designation MA6000 produced by INCO (cf. DE-A-No. 2,353,971). Corresponding alloys are furthermore known with a comparatively low chromium content (cf. K. Mino and K. Asakawa, "An oxide dispersion strengthened nickel-base superalloy with excellent high temperature strength", Transactions of the Iron and Steel Institute of Japan, vol. 27, pages 823-829, Tokyo, 1987).
It has already been proposed that the mechanical and thermal properties at medium and high temperatures, in particular, the ductility and the resistance to thermal fatigue (fatigue for comparatively low endurance) should be improved, in the case of conventional, non-oxide-dispersion-hardened nickel-base superalloys, by adding boron and carbon (cf. DE-A-No. 2,463,066; M. A. Burke, J. Greggi, G. A. Whitlow, The effect of boron and carbon on the microstructural chemistries of two wrought nickel base superalloys, Scripta metallurgica, vol. 18, pages 91-94, Pergamon 1984). However, there are no references whatsoever to oxide-dispersion-hardened superalloys. In addition, the mechanism of the recrystallization in the latter (so-called secondary recrystallization) is a completely different one to that of conventional alloys owing to the presence of non-coherent oxidic dispersoides.
SUMMARY OF THE INVENTION
Accordingly, one object of this invention is to provide novel, oxide-dispersion-hardened superalloys based on nickel which have an extended range of the temperature limits, compared with known alloys, for carrying out the annealing necessary for the production of coarse grain (secondary recrystallization). The object is, in particular, to provide a process for extending the temperature range of the secondary recrystallization which makes it possible to produce even monocrystals of large dimensions (cross section at least 5 cm2) by suitable annealing processes (for example, "zone annealing").
This object is achieved by a superalloy based on nickel as mentioned in the introduction which additionally contains boron in a content of 0.026 to 0.3 percent by weight.
This object is further achieved by a process as mentioned in the introduction, which comprises doping the oxide-dispersion-hardened nickel-base superalloy with a boron content of more than 0.011 percent by weight.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 15 percent by weight of chromium,
FIG. 2 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 20 percent by weight of chromium,
FIG. 3 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 17 percent by weight of chromium,
FIG. 4 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy with low chromium content.
FIG. 1 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 15 percent by weight of chromium. 1 is the curve for the variation of the recrystallization temperature, while 2 is the curve for the variation of the solidus temperature. ΔT is the maximum temperature range available for the secondary recrystallization. Below curve 1, no recrystallization takes place and an annealing with the object of growing coarse grain or even a monocrystal is pointless. Above curve 2, liquid phases occur and the unity of the crystals is destroyed. The dispersoides agglomerate and become ineffective as a hardening agent. According to curve 2, although the solidus temperature decreases slightly as the boron content increases, the recrystallization temperature according to curve 1 decreases considerably more markedly, as a result of which ΔT is extended.
FIG. 2 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 20 percent by weight of chromium. 3 is the curve for the recrystallization temperature, which falls off relatively steeply with increasing boron content, while 4 is the curve for the solidus temperature which has a substantially flatter variation. For a boron content of 0.03 percent by weight, the temperature range ΔT is already approx. 150° C.
FIG. 3 relates to a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy containing 17 percent by weight of chromium. 5 is the curve for the variation of the recrystallization temperature, while 6 is that for the variation of the solidus temperature. For a boron content of 0.035 percent by weight, the temperature range ΔT is approx. 145° C.
FIG. 4 shows a diagram of the variation of the recrystallization temperature and of the solidus temperature as a function of the boron content of an oxide-dispersion-hardened nickel-base superalloy with low chromium content. In the present case the latter was approx. 6 percent by weight. 7 is the curve for the variation of the recrystallization temperature, while 8 is the curve for the variation of the solidus temperature. For a boron content of 0.04 percent by weight, the temperature range ΔT is approx. 140° C.
It was possible to observe that, in all the oxide-dispersion-hardened nickel-base superalloy investigated, the temperature of the secondary recrystallization is decreased with increasing boron content. The magnitude of the effect of adding boron is variable and depends on the composition of the alloy. Apparently the chromium content plays an important role in this connection. In the case of alloys with a high chromium content, it was possible to detect a decrease in the recrystallization temperature of up to 50° C. per 0.01 percent by weight of boron added.
DESCRIPTION OF THE PREFERRED EMBODIMENTS EXEMPLARY EMBODIMENT 1
Referring now to FIG. 1, a fine-grain oxide-dispersion-hardened nickel-base superalloy which was extruded in the delivered state was investigated. The boron-free alloy had the following basic composition:
______________________________________                                    
Cr =            15     percent by weight                                  
W =             4.0    percent by weight                                  
Mo =            2.0    percent by weight                                  
Al =            4.5    percent by weight                                  
Ti =            2.5    percent by weight                                  
Ta =            2.0    percent by weight                                  
C =             0.05   percent by weight                                  
Zr =            0.15   percent by weight                                  
Y.sub.2 O.sub.3 =                                                         
                1.1    percent by weight                                  
Ni =            Remainder.                                                
______________________________________
Samples with different boron additions were produced, the total boron content being varied between 0 and approx. 0.05 percent by weight. The recrystallization temperature and solidus temperature were determined by conventional methods. The results are shown graphically in FIG. 1.
A prismatic body made from the above material containing 0.04 percent by weight of boron and having a thickness of 20 mm, a width of 50 mm and a length of 180 mm were subjected to a zone annealing process. It was possible to obtain longitudinally directed columnar crystals with, on average, a width of 25 mm, a thickness of 8 mm and a length of 60 mm.
EXEMPLARY EMBODIMENT 2
Referring to FIG. 2, the investigation related to a fine-grain oxide-dispersion-hardened nickel-base superalloy which was extruded in the delivered state. The boron-free alloy had the following basic composition:
______________________________________                                    
Cr =            20.0   percent by weight                                  
Al =            6.0    percent by weight                                  
Mo =            2.0    percent by weight                                  
W =             3.5    percent by weight                                  
Zr =            0.19   percent by weight                                  
C =             0.01   percent by weight                                  
Y.sub.2 O.sub.3 =                                                         
                1.1    percent by weight                                  
Ni =            Remainder.                                                
______________________________________
Test bodies with systematically increasing boron contents were produced, the boron values being varied between 0 and approx. 0.045 percent by weight. Both the recrystallization temperature and the solidus temperature were determined by conventional methods. FIG. 2 shows the results obtained in the process.
An aerofoil section with the following dimensions was machined from the above material containing 0.03 percent by weight of boron:
______________________________________                                    
Width =           92 mm                                                   
Maximum thickness =                                                       
                  22 mm                                                   
Section height =  26 mm                                                   
Length =          240 mm                                                  
______________________________________
The workpiece was subjected to a zone annealing process, and a monocrystal was produced.
EXEMPLARY EMBODIMENT 3
Referring to FIG. 3, a fine-grain oxide-dispersion-hardened nickel-base superalloy which was extruded in the delivered state was subjected to testing. The boron-free alloy had the following basic composition:
______________________________________                                    
Cr =            17.0   percent by weight                                  
Al =            6.0    percent by weight                                  
Mo =            2.0    percent by weight                                  
W =             3.5    percent by weight                                  
Ta =            2.0    percent by weight                                  
Zr =            0.15   percent by weight                                  
C =             0.05   percent by weight                                  
Y.sub.2 O.sub.3 =                                                         
                1.1    percent by weight                                  
Ni =            Remainder.                                                
______________________________________
Samples were prepared with different boron additions, the total boron content being varied between 0.005 and 0.05 percent by weight. The solidus temperature and the recrystallization temperature were each determined by usual known methods. The results are shown in FIG. 3.
A cylindrical body with a diameter of 40 mm and a length of 200 mm was machined from the above material containing 0.035 percent by weight of boron and subjected to a zone annealing process. The recrystallized structure was composed of longitudinally directed columnar crystals with, on average, a thickness on all sides of 10 mm and a length of 130 mm.
EXEMPLARY EMBODIMENT 4
Referring to FIG. 4, a fine-grain oxide-despersion-hardened nickel-base superalloy having a band structure which was hot-wrought in the delivered state was investigated. The alloy had the following basic composition:
______________________________________                                    
Co =            9.7    percent by weight                                  
Cr =            5.9    percent by weight                                  
Al =            4.2    percent by weight                                  
Mo =            2.0    percent by weight                                  
W =             12.4   percent by weight                                  
Ta =            4.7    percent by weight                                  
Ti =            0.8    percent by weight                                  
Zr =            0.05   percent by weight                                  
C =             0.05   percent by weight                                  
Y.sub.2 O.sub.3 =                                                         
                1.1    percent by weight                                  
Ni =            Remainder.                                                
______________________________________
Various contents of boron whose values ranged between 0.001 and 0.06 percent by weight were alloyed with the alloy of the basic composition. Both the solidus temperature and the recrystallization temperature were determined by the usual conventional methods. The results are shown graphically in FIG. 4.
A semi cylindrical body with a diameter of 55 mm and a length of 220 mm was machined from the above material containing 0.045 percent by weight of boron. The workpiece was subjected to a zone annealing process, a monocrystal being produced.
Obviously, numerous modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein and that the invention is not restricted to the exemplary embodiments.
The composition of the oxide-dispersion-hardened superalloys is as follows:
______________________________________                                    
Cr =           5-13.95  percent by weight                                 
Al =           2.5-7    percent by weight                                 
Mo =           0-2      percent by weight                                 
W =            0-15     percent by weight                                 
Ta =           0-7      percent by weight                                 
Hf =           0-1      percent by weight                                 
Ti =           0-3      percent by weight                                 
Zr =           0.02-0.2 percent by weight                                 
Co =           0-10     percent by weight                                 
C =            0-0.2    percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
               1-2      percent by weight                                 
Ni =           Remainder,                                                 
______________________________________
and also 0.026 to 0.3 percent by weight of boron or 0.026 to 0.1 percent by weight of boron.
Also:
______________________________________                                    
Cr =           14.05-22 percent by weight                                 
Al =           2.5-7    percent by weight                                 
Mo =           0-2      percent by weight                                 
W =            0-15     percent by weight                                 
Ta =           0-7      percent by weight                                 
Hf =           0-1      percent by weight                                 
Ti =           0-3      percent by weight                                 
Zr =           0.02-0.2 percent by weight                                 
Co =           0-10     percent by weight                                 
C =            0-0.2    percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
               1-2      percent by weight                                 
Ni =           Remainder,                                                 
______________________________________
and also 0.026 to 0.3 percent by weight of boron or 0.026 to 0.1 percent by weight of boron.
The following alloy furthermore also falls within the claimed composition:
______________________________________                                    
Cr =           18-22   percent by weight                                  
Al =           5-7     percent by weight                                  
Mo =           0-4     percent by weight                                  
W =            2-5     percent by weight                                  
Zr =           0.1-0.2 percent by weight                                  
C =            0-0.2   percent by weight                                  
Y.sub.2 O.sub.3 =                                                         
               1-2     percent by weight                                  
Ni =           Remainder,                                                 
______________________________________
and also 0.011 to 0.3 percent by weight of boron or 0.011 to 0.1 percent by weight of boron.
A further class of alloy has the following composition:
______________________________________                                    
Cr =            16-18  percent by weight                                  
Al =            6-7    percent by weight                                  
Mo =            2-2.5  percent by weight                                  
W =             3-3.5  percent by weight                                  
Ta =            2-2.5  percent by weight                                  
Hf =            0-1.5  percent by weight                                  
Zr <            0.2    percent by weight                                  
C <             0.1    percent by weight                                  
Y.sub.2 O.sub.3 =                                                         
                1-1.5  percent by weight                                  
Ni =            Remainder,                                                
______________________________________
and also 0.02 to 0.3 percent by weight of boron or 0.02 to 0.1 percent by weight of boron.
The following type of alloy is furthermore claimed:
______________________________________                                    
Cr =            16-18  percent by weight                                  
Al =            6-7    percent by weight                                  
Co =            8-10   percent by weight                                  
Ta =            5-7    percent by weight                                  
Zr <            0.2    percent by weight                                  
C <             0.1    percent by weight                                  
Y.sub.2 O.sub.3 =                                                         
                1-1.5  percent by weight                                  
Ni =            Remainder,                                                
______________________________________
and also 0.02 to 0.3 percent by weight of boron or 0.02 to 0.1 percent by weight of boron.
Among the alloys with lower chromium content, the following are claimed:
______________________________________                                    
Co =           0-10     percent by weight                                 
Cr =           5-17     percent by weight                                 
Al =           2.5-7    percent by weight                                 
Mo =           0-2      percent by weight                                 
W =            2.5-13   percent by weight                                 
Ta =           0-7      percent by weight                                 
Ti =           0.5-1.9  percent by weight                                 
Zr =           0.02-0.1 percent by weight                                 
C =            0-0.2    percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
               1-2      percent by weight                                 
Ni =           Remainder,                                                 
______________________________________
and also 0.011 to 0.3 percent by weight of boron or 0.011 to 0.1 percent by weight of boron.
Preferably, the alloy mentioned has the following composition:
______________________________________                                    
Cr =           13-17    percent by weight                                 
Al =           2.5-7    percent by weight                                 
Mo =           1-1.7    percent by weight                                 
W =            2.5-3.4  percent by weight                                 
Ta =           0-5      percent by weight                                 
Ti =           1-1.9    percent by weight                                 
Zr =           0.02-0.1 percent by weight                                 
C =            0-0.2    percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
               1-2      percent by weight                                 
Ni =           Remainder,                                                 
______________________________________
and also 0.011 to 0.3 percent by weight of boron or 0.011 to 0.1 percent by weight of boron.
A specific advantageous selection is represented by the following composition:
______________________________________                                    
Cr =            15     percent by weight                                  
Al =            5      percent by weight                                  
Mo =            1.7    percent by weight                                  
W =             3.4    percent by weight                                  
Ta =            4.5    percent by weight                                  
Ti =            1.9    percent by weight                                  
Zr =            0.1    percent by weight                                  
C =             0.05   percent by weight                                  
Y.sub.2 O.sub.3 =                                                         
                1.1    percent by weight                                  
Ni =            Remainder,                                                
______________________________________
and also 0.011 to 0.3 percent by weight of boron or 0.011 to 0.1 percent by weight of boron.
The novel process relates to the extension of the temperature range of the secondary recrystallization of an oxide-dispersion-hardened nickel-base superalloy during coarse-grain annealing of a workpiece and during annealing to produce a monocrystal of large dimensions having a cross section of at least 10 cm2, the oxide-dispersion-hardened nickel-base superalloy being doped with a boron content of more than 0.011 percent by weight. The doping is preferably 0.026 to 0.3 percent by weight of boron or 0.026 to 0.1 percent by weight of boron.
The advantages of the claimed alloys and of the novel process are in the greater freedom of the annealing process, in particular, of the zone annealing process, produced by extending the temperature range of the secondary recrystallization. This makes possible for the very first time the complete, satisfactory recrystallization to form coarse, longitudinally directed columnar crystals in the case of large workpiece cross sections to be treated. This is even more so for the annealing of a workpiece to produce a monocrystal of large dimensions. The novel process provides the possibility of producing turbine buckets of large cross section composed of a monocrystal, such as are required for modern industrial gas turbines of high power.

Claims (19)

What is claimed as new and desired to be secured by Letters Patent of the United States is:
1. An oxide-dispersion-hardened superalloy based on nickel which is composed of the following main constituents:
______________________________________                                    
Cr =          5-13.95   percent by weight                                 
Al =          2.5-7     percent by weight                                 
Mo =          0-2       percent by weight                                 
W =           0-15      percent by weight                                 
Ta =          0-7       percent by weight                                 
Hf =          0-1       percent by weight                                 
Ti =          0-3       percent by weight                                 
Zr =          0.02-0.2  percent by weight                                 
Co =          0-10      percent by weight                                 
C =           0-0.2     percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
              1-2       percent by weight                                 
Ni =          Remainder,                                                  
______________________________________
which additionally contains boron in a content of 0.026 to 0.3 percent by weight.
2. An oxide-dispersion-hardened superalloy as claimed in claim 1, which contains boron in a content of 0.026 to 0.1 percent by weight.
3. An oxide-dispersion-hardened superalloy based on nickel, which consists essentially of:
______________________________________                                    
Cr =           18-22    percent by weight                                 
Al =           5-7      percent by weight                                 
Mo =           0-4      percent by weight                                 
W =            2-5      percent by weight                                 
Zr =           0.1-0.2  percent by weight                                 
B =            0.011-0.3                                                  
                        percent by weight                                 
C =            0-0.2    percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
               1-2      percent by weight                                 
Ni =           Remainder.                                                 
______________________________________
4. An oxide-dispersion-hardened superalloy as claimed in claim 3, which contains boron in a content of 0.011 to 0.1 percent by weight.
5. An oxide-dispersion-hardened superalloy based on nickel, which consists essentially of:
______________________________________                                    
Cr =           16-18    percent by weight                                 
Al =           6-7      percent by weight                                 
Mo =           2-2.5    percent by weight                                 
W =            3-3.5    percent by weight                                 
Ta =           2-2.5    percent by weight                                 
Hf =           0-1.5    percent by weight                                 
Zr <           0.2      percent by weight                                 
B =            0.02-0.3 percent by weight                                 
C <            0.1      percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
               1-1.5    percent by weight                                 
Ni =           Remainder.                                                 
______________________________________
6. An oxide-dispersion-hardened superalloy as claimed in claim 5, which contains boron in a content of 0.02 to 0.1 percent by weight.
7. An oxide-dispersion-hardened superalloy based on nickel, which consists essentially of:
______________________________________                                    
Cr =           16-18    percent by weight                                 
Al =           6-7      percent by weight                                 
Co =           8-10     percent by weight                                 
Ta =           5-7      percent by weight                                 
Zr <           0.2      percent by weight                                 
B =            0.02-0.3 percent by weight                                 
C <            0.1      percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
               1-1.5    percent by weight                                 
Ni =           Remainder.                                                 
______________________________________
8. An oxide-dispersion-hardened superalloy as claimed in claim 7, which contains boron in a content of 0.02 to 0.1 percent by weight.
9. An oxide-dispersion-hardened superalloy based on nickel which consists essentially of:
______________________________________                                    
Co =           0-10     percent by weight                                 
Cr =           5-17     percent by weight                                 
Al =           2.5-7    percent by weight                                 
Mo =           0-2      percent by weight                                 
W =            2.5-13   percent by weight                                 
Ta =           0-7      percent by weight                                 
Ti =           0.5-1.9  percent by weight                                 
Zr =           0.02-0.1 percent by weight                                 
C =            0-0.2    percent by weight                                 
B =            0.011-0.3                                                  
                        percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
               1-2      percent by weight                                 
Ni =           Remainder.                                                 
______________________________________
10. An oxide-dispersion-hardened superalloy as claimed in claim 9, which contains boron in a content of 0.011 to 0.1 percent by weight.
11. An oxide-dispersion-hardened superalloy as claimed in claim 9, which consists essentially of:
______________________________________                                    
Cr =           13-17    percent by weight                                 
Al =           2.5-7    percent by weight                                 
Mo =           1-1.7    percent by weight                                 
W =            2.5-3.4  percent by weight                                 
Ta =           0-5      percent by weight                                 
Ti =           1-1.9    percent by weight                                 
Zr =           0.02-0.1 percent by weight                                 
C =            0-0.2    percent by weight                                 
B =            0.011-0.3                                                  
                        percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
               1-2      percent by weight                                 
Ni =           Remainder.                                                 
______________________________________
12. An oxide-dispersion-hardened superalloy as claimed in claim 11, which contains boron in a content of 0.011 to 0.1 percent by weight.
13. An oxide-dispersion-hardened superalloy as claimed in claim 11, which consists essentially of:
______________________________________                                    
Cr =           15       percent by weight                                 
Al =           5        percent by weight                                 
Mo =           1.7      percent by weight                                 
W =            3.4      percent by weight                                 
Ta =           4.5      percent by weight                                 
Ti =           1.9      percent by weight                                 
Zr =           0.1      percent by weight                                 
C =            0.05     percent by weight                                 
B =            0.011-0.3                                                  
                        percent by weight                                 
Y.sub.2 O.sub.3 =                                                         
               1.1      percent by weight                                 
Ni =           Remainder.                                                 
______________________________________
14. An oxide-dispersion-hardened superalloy as claimed in claim 13, which contains boron in a content of 0.011 to 0.1 percent by weight.
15. The oxide-dispersion-hardened superalloy of claim 1, wherein ΔT (recrystallization temperature minus solidus temperature) is at least 140° C.
16. The oxide-dispersion-hardened superalloy of claim 3, wherein ΔT (recrystallization temperature minus solidus temperature) is at least 140° C.
17. The oxide-dispersion-hardened superalloy of claim 5, wherein ΔT (recrystallization temperature minus solidus temperature) is at least 140° C.
18. The oxide-dispersion-hardened superalloy of claim 9, wherein ΔT (recrystallization temperature minus solidus temperature) is at least 140° C.
19. The oxide-dispersion-hardened superalloy of claim 11, wherein ΔT (recrystallization temperature minus solidus temperature) is at least 140° C.
US07/295,559 1988-01-18 1989-01-11 Oxide-dispersion-hardened superalloy based on nickel Expired - Fee Related US4995922A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH159/88 1988-01-18
CH159/88A CH674019A5 (en) 1988-01-18 1988-01-18

Publications (1)

Publication Number Publication Date
US4995922A true US4995922A (en) 1991-02-26

Family

ID=4180599

Family Applications (1)

Application Number Title Priority Date Filing Date
US07/295,559 Expired - Fee Related US4995922A (en) 1988-01-18 1989-01-11 Oxide-dispersion-hardened superalloy based on nickel

Country Status (3)

Country Link
US (1) US4995922A (en)
EP (1) EP0325760A1 (en)
CH (1) CH674019A5 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5316866A (en) * 1991-09-09 1994-05-31 General Electric Company Strengthened protective coatings for superalloys
US5427601A (en) * 1990-11-29 1995-06-27 Ngk Insulators, Ltd. Sintered metal bodies and manufacturing method therefor
US5455119A (en) * 1993-11-08 1995-10-03 Praxair S.T. Technology, Inc. Coating composition having good corrosion and oxidation resistance
US5712050A (en) * 1991-09-09 1998-01-27 General Electric Company Superalloy component with dispersion-containing protective coating
WO2004042101A2 (en) * 2002-11-04 2004-05-21 Dominique Flahaut High temperature alloys
WO2004042100A2 (en) * 2002-11-04 2004-05-21 Doncasters Limited High temperature resistant alloys
EP1903121A1 (en) 2006-09-21 2008-03-26 Honeywell International, Inc. Nickel-based alloys and articles made therefrom
US20110165012A1 (en) * 2009-07-29 2011-07-07 Marco Innocenti Nickel-based superalloy, mechanical component made of the above mentioned super alloy, piece of turbomachinery which includes the above mentioned component and related methods

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0447858B1 (en) * 1990-03-20 1995-05-24 Asea Brown Boveri Ag Process for producing an oxide dispersion strengthened superalloy article having a coarse grain structure directionally orientated along the length
DK166219C (en) * 1991-01-23 1993-08-16 Man B & W Diesel Gmbh VALVE WITH HAIR PILOT
CZ290109B6 (en) * 1991-08-02 2002-06-12 Isover Saint-Gobain Process for producing mineral wool from melted mineral material and apparatus for making the same
AU668878B2 (en) * 1992-08-20 1996-05-23 Isover Saint-Gobain Method for producing mineral wool, and mineral wool produced thereby
EP2431489A1 (en) * 2010-09-20 2012-03-21 Siemens Aktiengesellschaft Nickel-base superalloy
CN111379028A (en) * 2020-04-08 2020-07-07 中国科学院金属研究所 Ni-Al binary single crystal alloy, Ni-Al binary model single crystal alloy and preparation method thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2353971A1 (en) * 1972-10-30 1974-05-22 Int Nickel Ltd DURABLE DISPERSION REINFORCED NICKEL-CHROME ALLOY
US4386976A (en) * 1980-06-26 1983-06-07 Inco Research & Development Center, Inc. Dispersion-strengthened nickel-base alloy
US4668312A (en) * 1985-03-13 1987-05-26 Inco Alloys International, Inc. Turbine blade superalloy I

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2353971A1 (en) * 1972-10-30 1974-05-22 Int Nickel Ltd DURABLE DISPERSION REINFORCED NICKEL-CHROME ALLOY
FR2204700A1 (en) * 1972-10-30 1974-05-24 Int Nickel Ltd
US4386976A (en) * 1980-06-26 1983-06-07 Inco Research & Development Center, Inc. Dispersion-strengthened nickel-base alloy
US4668312A (en) * 1985-03-13 1987-05-26 Inco Alloys International, Inc. Turbine blade superalloy I

Non-Patent Citations (9)

* Cited by examiner, † Cited by third party
Title
G. H. Gessinger, Powder Metallurgy of Superalloys, Butterworths London, 1984. *
J. S. Benjamin, Metallurgical Transactions, vol. 1, Oct. 1970, pp. 2943 2951. *
J. S. Benjamin, Metallurgical Transactions, vol. 1, Oct. 1970, pp. 2943-2951.
K. Mino, et al., Transaction of the Iron and Steel Institute of Japan, vol. 27, pp. 823 829, Tokyo, 1987. *
K. Mino, et al., Transaction of the Iron and Steel Institute of Japan, vol. 27, pp. 823-829, Tokyo, 1987.
M. A. Burke, et al., Scripta Metallurgica, vol. 18, pp. 91 94, Pergamon 1984. *
M. A. Burke, et al., Scripta Metallurgica, vol. 18, pp. 91-94, Pergamon 1984.
R. F. Singer, et al., Conf. Proc., "High Temperature Materials for Gas Turbines", Liege, Belgium, Oct. 1986, pp. 1-30.
R. F. Singer, et al., Conf. Proc., High Temperature Materials for Gas Turbines , Liege, Belgium, Oct. 1986, pp. 1 30. *

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5427601A (en) * 1990-11-29 1995-06-27 Ngk Insulators, Ltd. Sintered metal bodies and manufacturing method therefor
US5316866A (en) * 1991-09-09 1994-05-31 General Electric Company Strengthened protective coatings for superalloys
US5712050A (en) * 1991-09-09 1998-01-27 General Electric Company Superalloy component with dispersion-containing protective coating
US5455119A (en) * 1993-11-08 1995-10-03 Praxair S.T. Technology, Inc. Coating composition having good corrosion and oxidation resistance
WO2004042101A3 (en) * 2002-11-04 2004-08-12 Dominique Flahaut High temperature alloys
WO2004042100A2 (en) * 2002-11-04 2004-05-21 Doncasters Limited High temperature resistant alloys
WO2004042101A2 (en) * 2002-11-04 2004-05-21 Dominique Flahaut High temperature alloys
WO2004042100A3 (en) * 2002-11-04 2004-08-19 Doncasters Ltd High temperature resistant alloys
US20060096673A1 (en) * 2002-11-04 2006-05-11 Dominique Flahaut High temperature alloys
US20100175508A1 (en) * 2002-11-04 2010-07-15 Dominique Flahaut High temperature alloys
EP1903121A1 (en) 2006-09-21 2008-03-26 Honeywell International, Inc. Nickel-based alloys and articles made therefrom
US20100028197A1 (en) * 2006-09-21 2010-02-04 Mark Heazle Nickel-based alloys and articles made therefrom
US7824606B2 (en) 2006-09-21 2010-11-02 Honeywell International Inc. Nickel-based alloys and articles made therefrom
US20110165012A1 (en) * 2009-07-29 2011-07-07 Marco Innocenti Nickel-based superalloy, mechanical component made of the above mentioned super alloy, piece of turbomachinery which includes the above mentioned component and related methods
US9359658B2 (en) * 2009-07-29 2016-06-07 Nuovo Pignone S.P.A Nickel-based superalloy, mechanical component made of the above mentioned super alloy, piece of turbomachinery which includes the above mentioned component and related methods

Also Published As

Publication number Publication date
EP0325760A1 (en) 1989-08-02
CH674019A5 (en) 1990-04-30

Similar Documents

Publication Publication Date Title
US4995922A (en) Oxide-dispersion-hardened superalloy based on nickel
Floreen et al. The metallurgy of alloy 625
JP2778705B2 (en) Ni-based super heat-resistant alloy and method for producing the same
US5154884A (en) Single crystal nickel-base superalloy article and method for making
US4818486A (en) Low thermal expansion superalloy
EP0184136A2 (en) Fatigue-resistant nickel-base superalloys
US4076525A (en) High strength fracture resistant weldable steels
US4386976A (en) Dispersion-strengthened nickel-base alloy
CA1066922A (en) Heat-resistant allow for welded structures
US4476091A (en) Oxidation-resistant nickel alloy
CA2010672A1 (en) Titanium aluminide alloys
JP3308090B2 (en) Fe-based super heat-resistant alloy
CA2146534C (en) Heat-resistant nickel-based alloy excellent in weldability
Ray et al. Microcrystalline iron-base alloys made using a rapid solidification technology
US4717435A (en) Gamma-prime precipitation hardening nickel-base yttria particle-dispersion-strengthened superalloy
US4857120A (en) Heat-resisting steel turbine part
Singh et al. Influence of ageing treatment on work hardening behaviour of a Ni-base superalloy
US5447582A (en) Method to refine the microstructure of α-2 titanium aluminide-based cast and ingot metallurgy articles
US2513470A (en) Ferrous alloy articles having great strength at high temperatures
US3635769A (en) Nickel-chromium eutectic alloy
US5067986A (en) Process for producing coarse, longitudinally oriented column crystals in an oxide-dispersion-strengthened nickel-base superalloy
Morral The Metallurgy of Cobalt Alloys—A 1968 Review
US4798625A (en) Superalloy with oxide dispersion hardening having improved corrosion resistance and based on nickel
US4195987A (en) Weldable alloys
EP0669403A2 (en) Gas turbine blade alloy

Legal Events

Date Code Title Description
AS Assignment

Owner name: ASEA BROWN BOVERI LTD., CH-5401 BADEN, SWITZERLAND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:JONGENBURGER, PETER;REEL/FRAME:005496/0753

Effective date: 19881220

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
FP Lapsed due to failure to pay maintenance fee

Effective date: 19950301

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362